Paper bag



July 31, 1934. T. HAYASHI 1,963,437

PAPER BAG Filed July 23, 1951 2 Sheets-Sheet 1 h "W "M" 1 a INVENTOR: //7 M BY MN ATTORNEYS July 31, 1934. T. HAYASHI, 1 1,968,487

PAPER BAG 7 Filed July 23/1931 Z Shee tS-W'Sheet 2 ATTORNEYS.

Patented July 31, 1934 UNITED STATES PAPER BAG Tomokiohi Kayashi, Asalruaa-Ku, Tokyo,

Japan Application July 28, 1831 Serial No. 552.595

1 Claim. (Cl. 229-59) This invention relates to a multiply paper bag made up of plurality walls of paper, or individual envelopes of paper, sodlsposed in relation,

one to the other that each envelope is inserted I into another one, and having as a particular feature that the wall of the paper bag is provided with a plurality of holes for the purpose of facilitating the expulsion of air-from the paper bag. Each of said holes is provided with torn flaps it) or pieces formed by a plurality of slits which are provided in the initial stages of manufacture by means of a pressing or a punching tool, said torn flaps or pieces acting as a valve. The essential object of this invention is to obtain a tough paper bag by which the task of filling up the same with cement or other substances is facilitated by readily expelling the air therefrom, while the entry of humidity into the bag through such holes is eifectively prevented.

In order to illustrate a paper bag made in accordance with this invention in actual practice, reference may be had to the accompanying drawings in which:-

Figure 1 shows a perspective view of a paper bag made in accordance with this invention.

Figure 2 is a perspective view of the paper bag, having its open end provided with slits.

Figure 3 is a perspective view of the top of the paper bag on an enlarged scale, showing the parts folded along the base lines of the slits.

Figure 4 is a section through the line A-A, of Figure 1, shown onan enlarged scale.

Figure 5 is a front view of the holes which serve as means to expel the air from the paper bag, shown on an enlarged scale.

In all the figures, the same numerals designate the same or similar parts.

Referring to the accompanying drawings, a cylindrical paper bag (1) having a bottom, is made of several walls of paper. or paper envelopes arranged or nested in such a way that each envelope is inserted into another one. and each of these eylindrically shaped envelopes has slits (2) (2), provided in a part adjacent to each end of each side of the top thereof, by which wing pieces (3) (4) and side pieces (5) (6) are formed, as shown in Figure 2. The wing-pieces. (3) and (4), located at relatively opposite sides to each other, are folded inwardly along the base lines of the slits (2) (2), while each side piece on one. side is pasted and thereby attached to the corresponding side piece on the opposite side. thus forming a plural walled or multiply paper envelope, since the individual envelopes are nested or inserted one within the other.

The innermost side of one side piece is attached by being pasted to the outermost side of one wing piece (4). so that the corners on said wing piece are wholly enclosed, leaving other wing piece (3) free. so as to enable the latter to serve as a non-return valve or port in order to enable the envelope to be filled up with cement or the like. Numerous holes or'ports (13) which serve to facilitate expulsion of air from the paper bag or envelope are provided in the side pieces (5) (6), and each of these ports has a valve composed of torn flaps or pieces, (10) (I1) (12), formed by several slits ('1) (8) (ii) which are provided in the initial stages of manufacture by a drill-like pressing tool penetrating the paper. It is preferable that the drill-like tool has a triangular cross-section, that is to say, having three vertices formed thereon.

Since the paper bag made accordingly to the present invention is one which is made up of cooperating individual. envelopes nested into a multiply unit, each of these envelopes serves as an individual or independent member. The inside of the innermost envelope is subjected to a uniform pressure-owing to the presence of the air initially contained in the bag. when cement powder or the like substance is filled into the bag with the result that the second envelope or that envelope located just on the outside of the innermost envelope is caused to expand thereby, the third envelope being also expanded by the escaping air. and so on. In this case, the several slits provided in every envelope are located in: zig-zag manner with respect to each other, though the ports (13) are-very small, so that the no air initially contained in the bag,.together with the cement powder or other contents causes the torn flaps or-pleces (10) (11) (12) provided in the walls of the innermost envelope to be pressed outwardly from the inside. .The flaps orjpieces P5 of each individual inner envelope thus pressed. are restrained and'limited by means of the next adiacent'envelope disposed thereover, and so on, whereby the airvis entirely expelled therefrom, mo the'eseape of cement or other powders being: prevented by means of the edges of the torn flaps or pieces (10) (11) (12). Consequently, the cement powder or other contents are never scattered or lost out of the paper bag, while the err try of humidity from without into the bag is prevented, as the ports (13) 'provided in several envelopes in a nested series are disposed in zigzag fashion with respect to each other. which resuits in preventing the deterioration of the eecessive walls of said multiply bag, which flaps in each associated group are formed by a plurality of interconnected slits and co-operate as a valve to facilitate the expulsion of air from said multiply bag, which associated groups of flaps in each individual walls are staggered in relation to the associated groups of flaps in the next ad- Jacent wall, the paper wall of one envelop being normally in contact with and tending to partly restrain and limit movement of the flaps disposed upon the adjacent wall immediately within or exterior to the same.

TOMOKICHI HAYASHI. 

